Devices for conveying sheets having two conveyor paths which intersect are often used in copying machines to feed originals or copies to or from processing stations. (See, for example, the device disclosed in U.K. Patent No. 1,397,605). This conveying device does not have any guide elements in the intersection of the conveying paths. One disadvantage of such a conveying device is that a sheet, particularly if it is limp, curled or damaged at the front edge, may stick in the intersection or take the wrong path and thus cause a malfunction in the copying machine.
Other conveying devices use sheet guides which switch between positions to direct the sheets in one direction or other. (See, for example, the device disclosed in U.S. Pat. No. 3,331,276). It is also known to combine a number of guides in order to form a system of intersecting conveyor paths. (See, for example, the devices disclosed in West German Offenlegungsschrift 3341413 and U.S. Pat. No. 4,264,067). To obtain a reliable conveying device using several guides, however, a number of switches and other elements are required as well as an extensive control and monitoring system. As a result, the entire arrangement becomes very complex, expensive and therefore unattractive for practical use.
Japanese Patent Application 58-202247 uses a cylindrical element having a slot in the form of an arc of a circle extending over the width as a guide. By rotating the cylinder, the location of the arced slot is changed and thus the direction of the conveyor paths. Japanese Patent Application 60-52458 discloses a paper inverter having an hour-glass shaped guide element which can be turned through 90.degree.. In the first position, a sheet can be conveyed from a feed section into a first inverter. By turning the element 90.degree. to a second position, the sheet can be conveyed from the first inverter to the discharge section while at the same time a second sheet can be conveyed from the feed section to a second inverter. Finally, in an intermediate position of 45.degree., the element contains a groove which directly connects the feed section and the discharge section. The problem with guide elements having slots and grooves as shown in these references is that they still may be blocked, especially if the sheet is limp, curled or damaged at the front edge.
It would be desirable, therefore, in a device for conveying sheets with two intersecting conveyor paths to have a simple path guide which obviated the above-described disadvantages and provided a compact, cheap and reliable conveying device using a minimum number of parts.